Juu Juuzawa is a delinquent who prefers solitude over making friends. Thus, when a girl named Ame Ochibana claims they have a connection from their past lives, he is skeptical and rejects her offer of friendship. Ame's desire to serve Juu only adds to his doubts and he tries to distance himself from her. However, when one of their classmates is killed, Juu suspects Ame to be the culprit and decides to keep her close. Unexpectedly, Ame's intelligence and abilities turn out to be helpful in solving the case, and the two start working together. Denpa-teki na Kanojo tells a tale of devotion, loss, and love, portraying how even the least expected individuals can become great allies.